If the song was imported as part of a playlist, or was added to a playlist before you experimented with changes, look there.(unless you were experimenting with one in a playlist)

If you can locate the song you imported in the forums, you could import it anew.

If you edit the title of your current chart in your song library to make a slight change (add a period, or anything),
When you reimport the (original) tune, your app won’t see it as a duplicate and add a number to the title.

)BOB